mfbt/UniquePtrExtensions.h
author Sylvestre Ledru <sledru@mozilla.com>
Mon, 06 Nov 2017 13:22:06 +0100
changeset 694109 98e2b4ee9775a2a2b5cc1bb8a390bfe901814f38
parent 335945 6d7c88d923886811a7d3608ec2f4b700cc30ba85
permissions -rw-r--r--
reformat all MozReview-Commit-ID: ApY4gI1IbKr

/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

/* Useful extensions to UniquePtr. */

#ifndef mozilla_UniquePtrExtensions_h
#define mozilla_UniquePtrExtensions_h

#include "mozilla/fallible.h"
#include "mozilla/UniquePtr.h"

namespace mozilla {

/**
 * MakeUniqueFallible works exactly like MakeUnique, except that the memory
 * allocation performed is done fallibly, i.e. it can return nullptr.
 */
template <typename T, typename... Args>
typename detail::UniqueSelector<T>::SingleObject MakeUniqueFallible(
    Args&&... aArgs)
{
  return UniquePtr<T>(new (fallible) T(Forward<Args>(aArgs)...));
}

template <typename T>
typename detail::UniqueSelector<T>::UnknownBound MakeUniqueFallible(
    decltype(sizeof(int)) aN)
{
  typedef typename RemoveExtent<T>::Type ArrayType;
  return UniquePtr<T>(new (fallible) ArrayType[aN]());
}

template <typename T, typename... Args>
typename detail::UniqueSelector<T>::KnownBound MakeUniqueFallible(
    Args&&... aArgs) = delete;

namespace detail {

template <typename T>
struct FreePolicy
{
  void operator()(const void* ptr) { free(const_cast<void*>(ptr)); }
};

}  // namespace detail

template <typename T>
using UniqueFreePtr = UniquePtr<T, detail::FreePolicy<T>>;

}  // namespace mozilla

#endif  // mozilla_UniquePtrExtensions_h